Abstract

A comprehensive model for photon noise and correlations in semiconductor cascade lasers is presented. Photon emission events in different gain sections of cascade lasers are correlated. These correlations are found to be positive and arise because the gain sections are connected electrically. The scaling of photon correlations and intensity noise with the number of cascade sections is discussed. The model presented in this letter is applicable to a variety of cascade laser structures including bipolar interband cascade lasers and unipolar intersubband cascade lasers. For comparison, photon noise and correlations in parallel lasers arrays are also discussed.